The proposed research work involves a number of statistical problems which arose from various projects in the Wisconsin Clinical Cancer Center and the related statistical theory and methodology needed to solve these problems. The main thrust of the research work has to do with the statistical analysis of survival data using censored data, i.e., data involving lifetimes some of which are complete (uncensored) and some of which are incomplete or lost to followup (uncensored). The research proposed includes attacking or extending work in the following areas: (1) studies of the Cox model for covariance analysis of survival data, (2) robust statistical analysis for censored data, (3) development of methods for median and mean survival analysis with censored data, (4) further investigation of a class of Bayesian estimators of survival curves, (5) the design problem of setting sample sizes to compare survival for a clinical trial of more than two arms, (6) development of further statistical computer programs for the analysis of survival data, and (7) Monte Carlo simulation studies of various methods of analysis of survival data. In addition to the above specific areas of statistical research, the four statisticians involved in the project will work on statistical research problems arising from their consultation work with various scientists in the Wisconsin Clinical Cancer Center.